The present invention relates generally to hybrid vehicles and more particularly to an automated manual transmission for overcoming traditional and hybrid vehicle deficiencies.
Automobile manufacturers continuously strive to improve the fuel efficiency of the vehicles they design. Fuel efficiency can be achieved through improvements in practically any feature of an automobile. Component weight, engine and transmission configuration and aerodynamics are just a few examples of the almost limitless areas increased efficiency can be achieved.
More recently, automobile manufacturers have ventured into the area of hybrid vehicles. A hybrid vehicle has both a traditional combustion engine and an electric motor/generator for driving the vehicle. A hybrid vehicle offers significantly increased fuel efficiency due to the assistance of the electric motor/generator. Although hybrid vehicles offer improved efficiency, the overall powertrain implemented with such a vehicle is still oversized for its application.
The powertrains of conventional and even hybrid vehicles are inefficient as they are designed to provide more power than required for the vehicle at cruising speeds. Specifically, the combustion engine of such powertrains is larger than required to provide power for acceleration and hill climbs. This extra power is not required for a vehicle once it is up to cruising speed. As a result, conventional vehicles are less efficient than desired.
Therefore, it is desirable in the industry to have an improved vehicle powertrain for implementation in a vehicle, such as a hybrid vehicle, which overcomes the inefficiencies inherent in a conventional powertrain.
In achieving the above identified objectives, the present invention provides an improved powertrain configuration comprising a split path transmission operable by a combustion engine and an electric motor/generator. The combustion engine drives the split path transmission while the electric motor/generator assists in such driving. In turn, the split path transmission communicates rotational motion to a rear differential for driving a pair of rear wheels. The split path transmission is operably attached to both an engine output and a first electric motor/generator by way of a planetary splitter and a lock-up clutch. A second electric motor/generator is implemented for driving a front differential. The split path transmission comprises three conventional plate clutches and three drive gear pairs for achieving six forward drive ratios. A reverse gear ratio is achieved using the first electric motor/generator. The first electric motor/generator initially generates power for powering the second electric motor/generator, for driving the vehicle at low speeds. It is also foreseen that the split path transmission may drive the front differential and the second electric motor/generator may drive the rear differential.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.